/Engine/Source/Runtime/AnimGraphRuntime/Public/RBF/RBFInterpolator.h
Returns a list of integer pairs indicating which distinct pair of nodes have the same weight as a pair of the same node. These result in an ill-formed coefficient matrix which kills the interpolation. The user can then either simply remove one of the pairs and retry, or warn the user that they have an invalid setup.
static bool GetIdenticalNodePairs ( const [TArrayView](API\Runtime\Core\Containers\TArrayView)< T > & InNodes, [WeightFuncT](API\Runtime\AnimGraphRuntime\RBF\TRBFInterpolator\WeightFuncT) InWeightFunc, [TArray](API\Runtime\Core\Containers\TArray)< [TTuple](API\Runtime\Core\Misc\TTuple)< int, int >> & OutInvalidPairs )